Seal



Aug. 23, 1966 H. T. MARTEN ETAL 3,267,535

SEAL

Filed May 26, 1965 United States Patent 3,267,535 SEAL Hollinshead T. Martin, Evanston, Ill., Arvid I. Ericsson,

Fort Lauderdale, Fla, and Ilmar J. Vilcins, Northhrook, Ill., assignors to Signode Corporation, a corporation of Delaware Filed May 26, 1965, Ser. No. 458303 6 Claims. (Cl. 24-16) This application is a continuation-in-part of application Serial No. 199,847, filed June 4, 1962, and now Patent No. 3,197,83 1.

The present invention relates to ligature joints and seals therefor and more particularly to seals and joints made with such seals surrounding overlapping poitions of ligatures such as strap. As used in the specification and claims hereof, the terms strap and strapping are used and intended to be generic to ligature elements substantially independent of the configuration thereof.

The type of ligature with which the present invention is concerned is referred to herein as plastic. As used, plastic refers to materials, natural or synthetic, which may be formed into an elongated ligature, which are readily deformable under pressures of the same order of magnitude as those ordinarily employed in sealing or forming joints in steel strapping, which are relatively soft compared to steel, which have good elastic and resilience properties, and which tend to conform to the shape of objects forced thereagainst, at room or normal atmospheric temperatures.

It has been found that in certain situations the elasticity or stretchability of the steel now used in strapping is less than that desired. This difiiculty is particularly apparent where the package is a compressible or expansible one which may have a tendency to swell or cause the strap to be subject to substantial shock loads. Swelling packages may burst straps that are not sufficiently stretchable or elastic, or create serious distortions in the package if the strap is too strong. These and other related problems such as the problem of disposing of removed or scrap strap have brought about a desire for the use of plastic strap. If the plastic strap is of a combustible material such as a nylon, it will be most easily disposed of in an incinerator.

Plastic materials were not effectively held when overlapping portions were secured together with known forms of seals used for steel strap. This was due to several features including those such as the slipperiness of the plastic and the transverse reduction in the dimensions thereof when the strap was subjected to substantial tensile forces. These problems were further multiplied when it was found that plastic strap had a tendency for cuts or tears therein to run until the strap shredded or separated.

In accordance with the present invention, most of these problems have been overcome and there is provided a new seal arrangement and joint arrangement which is highly effective with plastic strap to grip and hold the strap. In general, embodiments of this invention provide for gripping distortion of the strap by deformation of the strap engaging surface of the seal and the provision of a seal Which is substantially harder than the strap.

There are illustrated in the accompanying drawings and described hereinbelow in this specification two illustrative embodiments of the invention. In each of these, a seal 3,267,535 Patented August 23, 1966 ice of steel or other material harder than the plastic strap has a surface character or deformation of such character or configuration that when the seal is firmly pressed or squeezed into the overlapping portions of the strap there will be deformation of the strap to interlock the same with the seal and provide a rigid mechanical connection formed between the strap and the seal.

The hardness and strength of the seal are responsible for at least two important functions. First, when the seal is pressed firmly into engagement with the strap, the strap will be deformed to conform to the surface structure or character of the seal rather than the seal surfaces being smoothed or flattened out. Second, since a strap in tension has a tendency to open the seal and pull the folded or bent parts or sections apart, the character of the seal will result in the strap biting into the seal and thereby reduce the tendency of the seal to open and release the strap.

It should be understood, of course, that the foregoing statements as to the reasons for the advantages of a hander seal over a softer seal should not be considered as placing any limitations on the scope or substance of the invention. It has been found that a seal which is substantially harder than the plastic strap deforms the strap within the seal and provides an effective joint.

It has been found also, in accordance with this invention, that in order to effect a secure joint between the seal and the overlapping portions of the strap, that the irregular strap contacting surfaces of the seal should be such that they do not create a condition in the strap which would cause the strap to tear or shred.

The irregular configurations or character of the strap contacting surfaces of the seal may be provided in a number of different ways. The important aspect, however, is that they create a positive deformation of the strap without tearing the strap.

In one embodiment of the invention, the seal is formed of a body of hard sheet material such as steel, and it includes a center wall and a pair of flange walls. The center wall has parallel crossbars extending transversely thereof,

with spaces or slots between the crossbars. The flange walls are provided with irregular formations on their strap contacting surfaces, and, to seal the overlapping strap ends, the flange walls are bent around the overlapping portions and the seal is pressed into firm engagement with the strap. In this manner, the irregular formations cooperate with the spaces between the crossbars to undulate and deform the strap when the seal is closed thereabout.

In another embodiment of the invention, the body of the seal is wider than the strap to be secured thereby. The seal body is provided with a plurality of opposite and transversely extending fingers, which are opened to allow the ligature to be placed there'between. To securely join the overlapped strap ends, the oppositely extending fingers are bent toward one another to squeeze the strap ends between the fingers and other portions of the seal body.

A more detailed explanation of the invention is provided in the following description, and is illustrated in the accompanying drawing, in which:

FIGURE 1 is a perspective view of a seal embodying the teachings of one embodiment of the present invention;

FIGURE 2 is a plan view of a ligature joined by means of the seal of FIGURE 1;

FIGURE 3 is a sectional elevation thereof, taken along the line 3-3 of FIGURE 2;

FIGURE 4 is an elevational view of the ligature and seal of FIGURE 2;

FIGURE 5 is a plan view of a seal embodying the teachings of another embodiment of the present invention;

FIGURE 6 is a side view of the seal of FIGURE 5, with the fingers bent to allow positioning of a ligature therebetween; and

FIGURE 7 is a plan view of a ligature joined with the seal of FIGURE 5.

In the embodiment of FIGS. l4, an undulated strap configuration with positive gripping of the strap is provided by means of a seal it) having a center wall 12 and flange walls 14 and 15. Connected to the flange walls are bar-like formations 16 which are complementary with and are laterally aligned with respect to slots or openings 18, formed in the center wall 12 of the seal it Formations 16 may be formed integrally with the flange walls by deforming the walls to the desired configuration The body of the seal comprises a material, such as steel, which is harder than the plastic strap to be secured thereby. Steel sheet, 0.050 inch in thickness, has been found to be highly etfective. When the flange portions 14 and 15 are bent about the ligature, and the seal is closed and squeezed about the overlapped strap portions 24 and 22, the bar-like formations 1d register with and squeeze the strap into the slots 18. The forces exerted by the formations 16 against the strap cause an undulated configuration and positive gripping of the strap on the sides 24 of the crossbars 26 which remain in the center wall 12 of the seal when the slots 18 are formed therein.

An undulated strap configuration coupled with the biting of teeth elements into the strap ends is effected in the joint of FIG. 7, which utilizes the seal 30 of FIGS. 5-7. The seal blank shown in FIG. 5 has a series of I l-shaped punchings 32 taken therefrom so that the seal is provided with a plurality of transversely extending crossbars 34 and a plurality of transversely extending, half length biting and distorting fingers 3d.

The fingers 36 of the seal blank are bent outwardly from the center face of the seal, as shown in FIG. 6, to provide a receiving space for the overlapped strap end portions of the plastic strap 2 and 22. When the strap ends are received between the fingers 34, the fingers are then bent back to a position close to their original position, whereby the strap becomes wound about the fingers and the transversely extending crossbars, as shown in FIG. 7. This causes undulation of the strap, and by proper proportioning of the segments, the fingers and crossbars bite into the upper and lower strap end portions.

The features and structural configuration of the strap, joint and seal arrangements described are widely variable within the scope, concepts and principles of this invention. For example, toothed bars and fingers may be used with the slots and openings as well as various other formation configurations. Such configurations are within the scope of the invention, so long as there is a biting of the seal into the plastic strap and the seal is of greater hardness than the strap to effect biting and deformation thereof. These examples of such modifications are numerous, and it should be understood that the invention is not limited to the specific arrangements shown.

What is claimed is:

1. A seal for joining and securing a pair of overlapping strap portions of plastic material, which comprises: a unitary body of sheet material having a hardness which exceeds the hardness of the plastic strap to be secured thereby, said body including a center Wall and a pair of flange walls extending from the lateral extremities of the center wall, each of said flange walls having elongated protuberances extending laterally on its strap contacting surface, said center wall having a plurality of apertures each disposed in complementary relationship to a corresponding protuberance on each flange wall, said apertures having a dimension laterally of said body that is greater than the width of the strap to be secured by the seal whereby said protuberances register with said apertures to undulate the entire width of the strap when the flange walls individually overlie adjacent regions of the center wall.

2. A seal for joining and securing a pair of overlapping strap portions of plastic material, which comprises: a body of sheet material including a center Wall and a pair of flange walls, said flange walls having irregular formations on their strap contacting surf-aces, said center Wall comprising parallel crosslbars extending transversely thereof with spaces between said bars transversely aligned 'with said formations for accommodating a portion of the strap which is undulated by said irregular formations when the flange walls are closed about the strap and pressed into firm engagement therewith, said spaces extending across said sheet material a distance that is greater than the width of the strap to be secured by the seal.

3. A seal for joining and securing a pair of overlapping straps of plastic material, which comprises: a body of sheet material hai ing a hardness which exceeds the hardness of the plastic strap to be secured thereby, said body including a pair of longitudinally extending substantially parallel bends, said bends interconnecting a center Wall with a pair of flange walls, said center wall having a plurality of slots which extend laterally across its entire width and which extend into the flange walls to an extent at least equal to the thickness of the associated overlapped straps, said flange walls having a plurality of upstanding transversely extending generally bar-like formations disposed in complementary relationship with said slots, whereby the plastic strap engaged by said seal will be deformed and undulated by said formations cooperating with said slots.

4. A seal for joining and securing a pair of overlapping strap portions of plastic material, which comprises: a unitary body of steel sheet material about 0.050 inch in thickness and having -a hardness which exceed-s the hardness of the plastic strap to be secured thereby, said body including a center wall and a pair of flange walls extending from the lateral extremities of the center wall, each of said flange walls having elongated protuberances extending laterally on its strap contacting surface, said center wall having a plurality of apertures each disposed in complementary relationship to a corresponding protuberance on each flange wall, said apertures'having a dimension laterally of said body that is greater than the width of the strap to be secured by the seal whereby said protuberance-s register with said apertures to undulate the entire width of the strap when the flange walls individually overlie adjacent regions of the center wall.

5. A seal for joining and securing a pair of overlapping straps of plastic material, which comprises: a body of sheet material having a hardness which exceeds the hardness of the plastic strap to be secured thereby, said body being of a width that is greater than the width of the strap to be secured thereby, said body defining a plurality of adjacent generally H-shaped openings extending transversely with respect to said body to form a plurality of transversely and oppositely ext-ending fingers and a plurality of transversely extending parallel crossbars, said fingers being positioned longitudinally of and adjacent to said cross/bars, said fingers being adapted for angular positioning with respect to said crossbars to allow the strap to be positioned between opposite fingers, said fingers having non-rounded ends which are adapted to cooperate with the side portions thereof to bite into the plastic strap when the fingers are engaged therewith, and said fingers being adapted to engage one side of the overlapped straps and to cooperate with said crossbars to squeeze the overlapped straps between the fingers and the crossbars causing the fingers to bite into the strap when the fingers are closed about the overlapped straps.

6. A ligature of plastic strap having overlapped strap port-ions joined and secured together by a seal which includes a body of sheet m-aterial having a hardness which exceeds the hardness of said plastic strap, said :body including a center wall and a pair of flange walls, said center wall having a plurality of apertures and said flange walls having blunt irregular formations on their strap contacting surfaces, said flange walls being bent about said plastic strap so that said irregular formations are pressing portions of said overlapping strap portions into said apertures.

References Cited by the Examiner UNITED STATES PATENTS 117,202 7/ 1871 Peyton 24-22 1,245,455 11/1917 Gilchrist 24-17 1,436,448 11/ 1922 Kimball et al 24-23 6 2,118,158 5/1938 Carlson 24-23 2,273,007 2/ 1942 Cooper 24-23 2,988,391 6/ 1961 Erke 292-325 FOREIGN PATENTS 387,876 7/ 1908 France.

407,404 12/ 1924 Germany.

441,906 3/ 1927 Germany.

502,974 7/ 1930 Germany.

581,552 7/1933 Germany.

398,741 9/ 1933 Great Britain.

147,669 10/ 1961 Russia.

WILLIAM FELDMAN, Primary Examiner. D. GRIFFIN, Assistant Examiner. 

6. A LIGATURE OF PLASTIC STRAP HAVING OVERLAPPED STRAP PORTIONS JOINED AND SECURED TOGETHER BY A SEAL WHICH INCLUDES A BODY OF SHEET MATERIAL HAVING A HARDNESS WHICH EXCEEDS THE HARDNESS OF SAID PLASTIC STRAP, SAID BODY INCLUDING A CENTER WALL AND A PAIR OF FLANGE WALLS, SAID CENTER WALL HAVING A PLURALITY OF APERTURES ON SAID FLANGE WALLS HAVING BLUNT IRREGULAR FORMATIONS ON THEIR STRAP CON- 